A survey of the radiographic practices of general dentists for edentulous patients

Radiograph prescription practices of dentists in Ontario, Canada

BACKGROUND

With the advent of new ionizing radiation technologies, consideration must be given to the use of radiography in clinical practice. The authors aimed to determine how general dentists obtain oral and maxillofacial images and whether dentists' demographic characteristics and practice environments affect imaging decisions.

METHODS

The authors conducted a cross-sectional study using an electronic survey to collect information from general dentists in Ontario, Canada's most populous province.

RESULTS

The authors received 1,332 responses from 9,052 general dentists registered to practice in Ontario. A total of 57.2% of dentists used a nonindividualized approach to obtaining images for new adult dentate patients. Using clinical case scenarios, the authors found that 18.8% through 55.1% of dentists did not follow evidence-based guidelines when obtaining images. Overprescribing imaging was 5.8 times more common than underprescribing. Seeing patients after images were obtained (odds ratio [OR], 5.5), owning a panoramic and a cone-beam computed tomography imaging system (OR, 4.4), and the belief that images should be obtained to screen for occult pathoses (OR, 3.5) were the factors most strongly associated with overprescription.

CONCLUSIONS

Radiography prescription practices varied considerably among general dentists in Ontario and did not conform to established guidelines. Factors other than patient needs appeared to influence imaging practices.

PRACTICAL IMPLICATIONS

Overprescription of imaging by general dentists can result in unnecessary radiation exposure and financial costs to patients. To mitigate this, changes are needed in dental education, continuing education courses, and regulatory requirements.

The use of radiographic imaging technologies by general dentists in Ontario, Canada

OBJECTIVE

The aim of this study was to determine the prevalence of 2-dimensional and 3-dimensional digital imaging technologies, the methods used by general dentists to limit patient exposure to ionizing radiation, and the impact of dentists' education on imaging technologies and patient dose-reducing techniques.

STUDY DESIGN

A cross-sectional, web-based survey of all general dentists in Ontario was conducted.

RESULTS

Responses from 1332 (14.7%) of the 9052 registered general dentists in Ontario were included in the analysis. Approximately 89% reported using digital intraoral technology, 81.1% reported owning panoramic imaging systems, 71.2% reported making referrals for cone beam computed tomography (CBCT), and 9.5% reported including CBCT in their practices. CBCT was most commonly used for dental implant treatment planning (85.8%), followed by endodontics (45.4%), evaluation of pathology (39.6%), and surgical assessment for impacted teeth or difficult extractions (36.8%). Approximately 32.7% used only collimators with a long focal point-receptor distance and 8% used only rectangular collimation; 86.9% reported using a thyroid collar when imaging patients. Differences in educational backgrounds correlated with differences in the use of imaging and dose-reducing techniques.

CONCLUSIONS

There is widespread adoption of digital imaging technologies by general dentists in Ontario, including CBCT. Greater implementation of long and/or rectangular collimation could markedly reduce the ionizing radiation dose to patients. Changes in dental education curricula and continuing education course offerings may address these issues.

Panoramic radiographs made before complete removable dental prostheses fabrication: A retrospective study of clinical significance

STATEMENT OF PROBLEM

The value of digital panoramic radiographs to screen for problems before fabricating conventional complete dentures is unclear.

PURPOSE

The purpose of this retrospective study was to examine the influence of pretreatment digital panoramic radiographs on the clinical management of patients receiving complete removable dental prostheses.

MATERIAL AND METHODS

The clinical records, including panoramic radiographs, of 169 patients seeking new complete removable dental prostheses over a 6-year period were interpreted independently by both a prosthodontist and an oral and maxillofacial radiologist to identify radiographic findings that influenced clinical patient management. A 95% confidence interval and an observed proportion of agreement were used to interpret the results.

RESULTS

Sixty percent of the 169 radiographs examined had 1 or more abnormal or positive radiographic findings; however, only 6 (<4%) of 165 abnormalities detected influenced patient management, and 3 of them were identified during the clinical examination.

CONCLUSIONS

Pretreatment digital panoramic radiographs revealed very few abnormalities that influenced the treatment of patients requiring complete removable dental prostheses. Furthermore, the digital images in this study revealed positive findings at a rate similar to those found in studies assessing analog radiographs, reinforcing current guidelines that recommend against radiographic screening of patients who seek new complete removable dental prostheses.

Evaluation of calcified carotid atheroma on panoramic radiographs and Doppler ultrasonography in an older population

Aim

The aim of this study is to determine the reliability of panoramic radiograph (PR) as a screening tool for the detection of calcified carotid atheroma (CCA) by comparing it with Doppler ultrasonography (DU) examination. A second aim was to evaluate the relationship among CCA, systemic diseases, smoking, and body mass index in an older population.

Materials and methods

A total of 1,650 PRs of patients aged over 45 years (736 males and 914 females) were randomly selected. All the patients had been referred to the Faculty of Dentistry, Afyon Kocatepe University, Afyonkarahisar, Turkey, during 2013–2014 for routine PR screening. Medical data were collected from the archival records of the dental school. The patients were divided into two groups: Group A (study group), CCA findings were confirmed by DU (n=59); and Group B (control group), CCA findings were not confirmed by DU (n=34).

Results

Of the 1,650 individuals, 93 (5.63%) were detected to have CCA on PR. The population consisted of 43 males and 50 females with mean age of 59.84±10.92 years. No difference was determined in respect of CCA between the sexes (P=0.745). There was a significant difference between Group A and Group B in respect of hypertension (P=0.004). But there was no difference between Group A and Group B in respect of age (P=0.495), BMI (P=0.756), diabetes (P=0.168), and smoking (P=0.482) distribution.

Conclusion

Although PR cannot be used as an initial diagnostic method when searching for CCA, dentists should be aware of CCA on a routine PR, particularly in older patients who may also have the risk factors of obesity, diabetes mellitus, hypertension, and smoking. Recognizing of CCA especially in hypertensive patients could potentially increase the length and quality of life for individuals.

A new bite block for panoramic radiographs of anterior edentulous patients: A technical report

Purpose

Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues.

Materials and Methods

A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device.

Results

Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block.

Conclusion

Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

Comparison of the reproducibility of panoramic radiographs between dentulous and edentulous patients

Purpose

This study was performed to evaluate the reproducibility of panoramic radiographs of dentulous and edentulous patients.

Materials and Methods

The reproducibility of panoramic radiographs was evaluated using the panoramic radiographs acquired from 30 anterior dentulous patients by using a common biting positioning device (dentulous group) and 30 anterior edentulous patients by using chin-support devices to take a panoramic radiograph (edentulous group), respectively; these patients had undergone 3 or more panoramic radiographs. The widths and angles between the designated landmarks were measured on the panoramic radiographs, and the reproducibility was evaluated using the intraclass correlation coefficient (ICC) and the coefficient of variation.

Results

In the dentulous and edentulous groups, the ICCs of the mandibular ramus and mandibular angle areas were higher than the condylar head and zygomatic areas. The mandibular ramus and angle areas showed statistically lower mean coefficients of variation than the condylar head and zygomatic areas in the dentulous group. The mandibular angle area showed a significantly lower mean coefficient of variation than the zygomatic area in the edentulous group. By comparing the two groups, each ICC of the edentulous group was lower than that of the dentulous group, and the mean coefficients of variation of the mandibular ramus area, zygomatic area, left condylar inclination, and ramus ratio between the right and the left in the edentulous group were significantly higher than those in the dentulous group.

Conclusion

Biting positioning for dentulous patients provided better positioning reproducibility than chin-support positioning when performing panoramic radiography for edentulous patients.

Accuracy of computerized vertical measurements on digital orthopantomographs: posterior mandibular region

OBJECTIVES

Orthopantomographs are commonly used for diagnosis in clinical dentistry. Although the manufacturers claim a constant magnification effect, the reliability of measuring dimensions on the panoramic radiographs is not clear. The aim of this study was to evaluate the accuracy of measuring vertical dimensions in the posterior mandibular area on digital orthopantomographs.

MATERIALS AND METHODS

A retrospective survey of 20 orthopantomographs with unrestored implants (only with cover screw) in the mandibular posterior region (molars and premolars) was conducted. All radiographs were taken using the same machine by skilled technicians. Two examiners were asked to measure the vertical dimension of the implants seen on the radiographs viewed using two differently sized display screens. Inter-examiner and intra-examiner reliability tests were performed. Differences between the measured length and the actual length using each screen type were compared.

RESULTS

High coefficients of reliability were observed on intra- and inter-examiner correlation. The overall reliability of measuring the vertical dimensions of implants between both examiners for the large screen and the small screen were 97.4% (Cronbach's alpha 0.993) and 94.0% (Cronbach's alpha 0.984), respectively. There were no significant differences between the errors seen with either the large screen or the small screen, when each of them was compared to the original length (P = 0.146).

CONCLUSION

This study shows that vertical dimensions in the posterior mandibular region (molar and premolars) can be reliably measured on an orthopantomograph using a calibrated machine and special software.

Questionnaire surveys of dentists on radiology

OBJECTIVES

Survey by questionnaire is a widely used research method in dental radiology. A major concern in reviews of questionnaires is non-response. The objectives of this study were to review questionnaire studies in dental radiology with regard to potential survey errors and to develop recommendations to assist future researchers.

METHODS

A literature search with the software search package PubMed was used to obtain internet-based access to Medline through the website www.ncbi.nlm.nih.gov/pubmed. A search of the English language peer-reviewed literature was conducted of all published studies, with no restriction on date. The search strategy found articles with dates from 1983 to 2010. The medical subject heading terms used were "questionnaire", "dental radiology" and "dental radiography". The reference sections of articles retrieved by this method were hand-searched in order to identify further relevant papers. Reviews, commentaries and relevant studies from the wider literature were also included.

RESULTS

53 questionnaire studies were identified in the dental literature that concerned dental radiography and included a report of response rate. These were all published between 1983 and 2010. In total, 87 articles are referred to in this review, including the 53 dental radiology studies. Other cited articles include reviews, commentaries and examples of studies outside dental radiology where they are germane to the arguments presented.

CONCLUSIONS

Non-response is only one of four broad areas of error to which questionnaire surveys are subject. This review considers coverage, sampling and measurement, as well as non-response. Recommendations are made to assist future research that uses questionnaire surveys.

Correlating carotid artery stenosis detected by panoramic radiography with clinically relevant carotid artery stenosis determined by duplex ultrasound

OBJECTIVE

We sought to assess the utility of panoramic radiography as an adjunct screening tool for detecting significant asymptomatic carotid artery stenosis. The specific aim was to correlate calcifications seen in the region of the carotid bifurcation with clinically relevant carotid artery stenosis as determined by duplex ultrasound (DUS).

STUDY DESIGN

Routine dental panoramic films of patients 55 and older (n = 778) at the University of Rochester Eastman Dental Center were retrospectively reviewed for calcifications around the carotid bifurcation. Patients with such calcifications were referred for DUS, and raw data were interpreted by a vascular surgeon blinded to the radiographic findings. Groups were compared by using the chi(2) test.

RESULTS

Twenty-seven patients (3.5%) had suggestive radiographic calcifications on one or both sides, 20 of whom consented to DUS. Clinically significant carotid stenoses (>50% lumenal narrowing) were present in 50% of the sides with calcification compared with 21% of the sides without (P =.08, chi(2)). Three patients (15% of those screened with DUS) had stenoses greater than 80% and underwent 4 carotid endarterectomies as a direct result of screening.

CONCLUSIONS

Data suggest that clinically significant stenosis may exist if calcifications are observed on panoramic radiographs. Incidental examination of this area carries a minimal cost and appears beneficial as a screening tool for carotid disease, although definitive testing must follow.

Evaluation of the precision of dimensional measurements of the mandible on panoramic radiographs

The purpose of this study was to evaluate the precision of dimensional measurements of the mandible on orthopantomographic images and thus to evaluate their dimensional reliability. Different distances denoted by metal markers were measured on 25 dry mandibles. The same mandibles were then positioned in an orthopantomographic machine, and radiographic images of them were made. Measurements of the same distances were made on the panoramic images and then compared with the results of the measurements on the dry mandibles. All results were statistically analyzed. The results showed significant difference between the magnification factor listed by the manufacturer and calculated magnification factors, the latter being closer to 1.00. The study also showed that linear measurements made on only one side of the panoramic image of a mandible were very close to the actual dimensions of the dry mandible, whereas measurements that extended across the midline of the mandible were greatly enlarged because of large magnification factors; therefore, such measurements should not be made.

An analysis of the scientific basis for the radiographic guideline for new edentulous patients

The FDA Radiology Guideline for the new edentulous patient recommends an initial survey of the arches. In the process of developing this recommendation, the expert panel reviewed the available literature and concluded that there was sufficient evidence to warrant screening radiography rather than selective radiography, which is the principle on which all the other recommendations are based. Our evaluation of the literature used by the panel for the edentulous recommendation identifies critical errors in the analysis of the data. Factors such as a vague definition of abnormality and a geographically diverse sample population might have led the expert panel to suggest a very conservative recommendation for this group of patients. The recommendation failed to consider the treatment impact of findings and was based simply on the large number of observations, regardless of their treatment or pathologic significance. However, in studies in which treatment is considered, it is clear that screening radiography for new edentulous patients does not yield sufficient clinically relevant information to support the guideline.